A mechanical pencil is provided which does not require operation of removing or re-fitting a cap but allows writing immediately after supplying a writing lead. A lead fixing chuck 4 which is moved back and forth in conjunction with knock operation of a knock bar 22 to release and grip the writing lead L, and a holder chuck 9 which is provided in front of the lead fixing chuck and holds the writing lead frictionally are arranged such that the writing lead can be gradually inched out by repeating the knock operation. An open/close mechanism having an open/close valve 27 is provided in which a writing lead feeding unit is opened in a situation where the grip of the lead fixing chuck 4 on the writing lead is released by the knock operation, and the holder chuck 9 is disposed proximate to a writing lead outlet.